A number of devices or apparatuses have been developed to collect blood from the body cavity of a patient into a remotely located device and then to re-infuse the collected blood back into the patient. This practice has been found to be beneficial and advantageous in a number of respects and circumstances. A number of the remotely located devices may generally be categorized as a collection bag in which the blood is collected and which is then used later as the source of blood for re-infusion. There are, however, a number of shortcomings with such prior art collection bags as will be explained on connection with the following examples.
Three different devices for the collection and reinfusion of blood are described in U.S. Pat. No. 4,573,992 granted to Marx. For one such device (See FIG. 1 & 1a thereof) a flexible collection bag is housed within a rigid receptacle, where blood is collected in the flexible bag by creating suction forces within the flexible bag. U.S. Pat. No. 5,275,585 granted to Olson also discloses another device that employs a flexible container or bag within a rigid outer container. Prior to use, the flexible bag is expanded so it generally conforms to the interior surface of the rigid receptacle. Also, a through aperture is described in the rigid container that communicates with the space between the flexible bag and the rigid container is sealed off or is interconnected to a suction source. In this way, when suction forces are established within the flexible bag, the bag will not collapse. It is further described that following collection of blood, the through aperture can be interconnected to a pressure source so the blood can be re-infused under pressure.
Such devices are cumbersome. Also the container within a container design of these devices makes it difficult to quickly and accurately determine the amount of blood that was collected in the flexible bag and then re-infused back into the patient. Also, proper operation of these devices requires that the interior of the rigid container does not communicate with outside air and/or is interconnected to a suction source. As such, pressure tight conditions must be established for all the penetrations through the housing. This increases the complexity and use of the device. Also, in some cases reduced pressure conditions in the space between the rigid container and outside the flexible bag are established to create the suction forces within the flexible bag.
The other embodiments described in U.S. Pat. No. 4,573,992 (see FIGS. 2 & 3 thereof) employ a concertina-like container having two ports at opposite ends of the container. In an embodiment shown in FIG. 2 of this patent, one port is interconnected to a drain line from the patient and the other port is interconnected to a suction source. Also, the concertina-like structure is configured so it does not compress substantially in the radial direction when a reduced pressure condition is established within the container but the container may be compressed in the axial direction. This embodiment further includes a rigid frame structure that is external to the container and extends axially between the two ports, and which cooperates with the configuration of each port to keep the concertina-like container in an extended condition while collecting blood. After the container is filled and after the container has been appropriately reconnected for re-infusion, the rigid structure is removed and the concertina-like container is mechanically or manually compressed axially to force the blood out of the container.
In a further embodiment shown in FIG. 3 of the Marx patent, the concertina-like structure is configured to have an inherent resiliency so it will automatically expand axially and return to its expanded condition after it has been axially compressed. It is further provided that a spreading spring means, extending between the two ports, can be provided to augment or replace the inherent resiliency of the concertina-like container. In use, the container is compressed axially to its minimum volume by an external force and the suction port of the container is interconnected to a clamped off suction line to the body cavity. The clamp is slowly released and the inherent resiliency of the container and/or the spreading spring means causes the container to extend axially thereby drawing blood therein. After the container is filled with blood, the container is mechanically or manually compressed so as to force the blood out of a separate port in the container to enable the blood to be pressure re-infused into the patient.
The concertina-like container devices disclosed in the Marx patent are cumbersome and not easy to use. Also, these devices are configured to be used in pressurized re-infusion applications and do not lend themselves to gravity feed applications. In order to gravity feed using a concertina-like container, it would be necessary to vent the container while the blood is being removed. As to the second embodiment in the Marx patent and because of the design and intended use of this embodiment, the device is also configured with internal check valves to prevent, for example, the admission of air through one of the ports when drawing blood into the container. Such check valves and other design features of the second embodiment increase the manufacturing complexity of the device. Notwithstanding these check valves, it is still possible for air to be drawn into the container for example, by drawing in both blood and air from the body cavity. Thus, a container may not be filled with blood even though it has been expanded to its maximum extent.
There are other types of collection or blood recovery bags that are configured with a spring type of mechanism to bias the bag open and keep it open when suction conditions are established within the bag. This allows blood to be drawn out of the body cavity and into the collection bag. These internal spring mechanisms act on the interior surfaces of the collection bag to keep the bag open under suction pressure conditions.
For example, one application of an internal spring mechanism consists of a metal spring acting on two opposing plastic members that in turn act on the opposing inside surfaces of the bag. Additionally, the plastic members are usually configured with a latching mechanism to keep the spring compressed so as to minimize the size of the collection bag for shipment and storage. Such types of collection bags are described in U.S. Pat. No. 4,429,693 granted to Blake et al. and U.S. Pat. No. 5,380,314 granted to Herweck et al.
Because internal spring members come into contact with the patient's blood, they must be manufactured of materials that do not pose a health risk or lead to blood contamination. Additionally, these internally located members can cause mechanical trauma to the blood being collected and/or re-infused. Thus, these members must be particularly constructed and configured so as to minimize such mechanical trauma.
When blood is being re-infused, it is desirable to be able to gravity feed the collected blood from the collection bag to a re-infusion device or directly to the patient. Typically blood bags for transfusion or other such fluid filled bags in a hospital or treatment facility are configured so that the fluid can be withdrawn from the bag and infused into the patient by gravity without requiring the bag to be vented. In order to withdraw fluid from a collection bag with an internal spring mechanism, however, the bag must be vented so the collected fluid can be gravity feed to the re-infusion device or patient.
Venting involves configuring the bag with another port that remains sealed while the blood is being collected. This vent is then opened while the blood is drained out of the bag. Additionally, to minimize blood contamination, the vent includes a filter member to filter the air before it enters the collection bag. In any event, the admission of air into the collection bag during re-infusion raises the concern of entrapping air or air bubbles in the blood being re-infused along with the related medical concerns if such blood were re-infused into the patient's circulatory system. Furthermore, if the vent is inadvertently left open or partially open while collecting blood, then the suction device may not suction the blood properly into the bag and may also create conditions involving the entrainment of the air in the collected blood.
Alternatively, a user could apply an external force to overcome the spring instead of venting the bag. However, the spring mechanism typically employs a spring that develops a relatively large force and a user does not easily overcome this force. This is particularly a problem considering the relatively small size and fluid capacity of the collection bag which may be about 700 ml or less and a force applied to such bags may be on the order of a 30 pound force. In addition, these types of bags do not lend themselves to the use of a pressure cuff where a user may apply an external force to the blood bag by means of a pressure cuff to force the blood out of the bag and under pressure.
As noted above, the plastic members that constitute a part of the spring mechanism typically include a latching mechanism so the spring is held in a compressed state and to hold the bag in a collapsed condition for purposes of shipping and storage. Because the latching mechanism is designed for easy actuation by a user, it is not uncommon for the latching mechanism to release during shipment, while they are being handled and/or while they are in storage. When the latching mechanism is released, the spring automatically opens the collection bag. Therefore, once the spring has been triggered by the release of the latching mechanism, it is very difficult, and in some cases impossible, to re-collapse the bag and re-latch the latching mechanism. For example, the latch may be designed as a single use device and may break when it is inadvertently released so the device cannot be re-latched. The presence of a foreign object within the collection bag may also make the bag unsuitable for other uses.
Other devices or apparatuses that are used for to evacuate or drain a wound by suction means and for blood collection and transfer are shown in U.S. Pat. Nos. 4,559,035, 4,443,220, 4,161,179, 3,993,067 and 4,424,053.
It thus would be desirable to provide a new collection bag or device and methods for collecting and re-infusing blood. It would be particularly desirable to provide such a collecting device and method that would minimize mechanical trauma to the collected and re-infused blood in comparison to prior art devices and allow blood to be easily re-infused by gravity or pressure feed without requiring simultaneous venting of the collection device. It is also desirable to provide such a device that minimizes the risk of inadvertent actuation during shipment, handling or storage as compared to prior art devices. Such collection devices are preferably simple in construction and less costly than prior art devices and use simple methods to utilize the device.